The findings show that unless a cleanup programme is implemented, PCBs in the Upper Hudson River pose an ongoing risk to human health and the environment as far as south of the Federal Dam at Troy, NY. Fish consumption advisories are currently in effect for the entire Hudson River.

Up to 500,000kg of PCBs were discharged into the Hudson by two General Electric capacitor manufacturing plants located in Fort Edward and Hudson Falls, NY between 1947 and 1977, according to the EPA (see related story).

PCBs are known to cause cancer in animals. Scientists therefore believe they are carcinogens in humans. Other long-term health effects of PCBs observed in laboratory animals include a reduced ability to fight infections, low birth weights, and learning problems.

The findings are based on two baseline risk assessments carried out by the EPA. In the Human Health Risk Assessment for the Mid-Hudson River, EPA evaluated cancer and non-cancer health effects of PCBs on humans, from the Federal Dam at Troy, NY to just south of Poughkeepsie, NY.

The EPA has said it will use these risk assessments to help establish acceptable exposure levels and evaluate various cleanup alternatives for the PCB-contaminated sediments in the Upper Hudson River.

The research found that eating fish from the Mid-Hudson River is the primary way humans are exposed to the PCBs. For every 10,000 people eating an average of one meal a week of fish caught in the Mid-Hudson, this exposure to PCBs incurs an increased risk of four additional cases of cancer. This increased cancer risk is about 100 times higher than EPA’s levels set under the US Government’s Superfund law.

For non-cancer health effects, the research found that eating an average of one meal a week of fish caught in the Mid-Hudson can expose the consumer to PCB levels 30 times higher than the EPA’s ‘level of concern.’

If no cleanup is implemented or no institutional controls are in place, the cancer risks and non-cancer health hazards would be above EPA’s generally acceptable levels for the 40-year exposure period evaluated in the report, the research shows.

However, the Human Health Risk Assessment shows that risks from exposure to PCBs through other means, such as drinking river water or recreational pursuits were shown to be significantly below EPA’s levels of concern.

The second report, the Ecological Risk Assessment, evaluates the future risks to 15 fish and wildlife species in the Lower Hudson River (Federal Dam at Troy to the Battery at New York City).

The Ecological Risk Assessment found that risks to fish and wildlife are greatest in the upper reaches of the Lower Hudson River and decrease as PCB concentrations drop off down river. Under baseline conditions for the Upper Hudson River, many species in the Lower Hudson River are expected to be at risk for decades to come.

The research found that larger fish that eat other fish, such as the largemouth bass and striped bass, are especially at risk from PCB exposure. Fish-eating birds and mammals, such as the belted kingfisher, great blue heron, mink and river otter, are also at risk. It is thought PCBs may affect the survival and reproduction of these animals.

The research claims that future concentrations of PCBs in water and sediments in the Lower Hudson River will exceed standards and guidelines established to be protective of the environment for decades to come. It is also thought that endangered species and animals living along the river designated as significant habitats, may be adversely affected by the PCBs in the future.

The risk assessments are companion reports to two earlier assessments, released by the EPA in August 1999, which evaluated risks to human health and the environment from PCBs in the Upper Hudson (Hudson Falls to the Federal Dam at Troy). The earlier reports concluded that PCB contamination in the Upper Hudson poses considerable risks to human health and the environment. All four risk assessment reports will be peer reviewed in May.

Action inspires action. Stay ahead of the curve with sustainability and energy newsletters from edie